Heat transfer processes and equipment for industrial applications

ABSTRACT

Embodiments of the present invention permit the transfer of heat energy from one process fluid to another in an industrial process without the need for an energy field or centralized energy storage. Preferred embodiments include one or more heat transfer modules that draw heat from one process fluid into circulating refrigerant in an evaporator heat exchanger and supply that heat to a different process fluid in a condenser heat exchanger. In some embodiments, adjustments are made to one or more parameters of one or more process fluids to ensure the desired heat transfer is accomplished with the heat transfer module&#39;s compressor operating near optimum efficiency.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. §119(e) to U.S.provisional application 61/313,517, filed Mar. 12, 2010, the entirety ofwhich is hereby incorporated by reference herein.

BACKGROUND

In industrial processes, process fluids are usually required for addingheat energy in some sub-processes and absorbing heat energy in othersub-processes. Warming process fluid so that it can supply heat energyin sub-processes typically requires natural gas or other independentheat source. Similarly, cooling process fluid so that it can absorb heatenergy in sub-processes typically requires some type of independentrefrigeration cycle.

Some systems aim to use some of the heat from one process fluid toanother in an industrial process without independent heat energy sourcesor sinks, but such systems use a central energy storage mechanism. Onesuch energy storage mechanism is an energy field. In a typical heat pumpapplication (such as a geothermal heating/cooling system) theconstruction of the energy field can exceed 50% of the total projectcost. In addition, energy fields require a significant amount ofphysical space that in many potential applications is simply notavailable. Furthermore, transferring energy into and out of thecentralized storage system itself requires energy reducing the overallsystem efficiency.

SUMMARY

Embodiments of the present invention permit the transfer of heat energyfrom one process fluid to another in an industrial process without theneed for an energy field or centralized energy storage. Preferredembodiments include one or more heat transfer modules that draw heatfrom one process fluid into circulating refrigerant in an evaporatorheat exchanger and supply that heat to a different process fluid in acondenser heat exchanger. In some embodiments, adjustments are made toone or more parameters of one or more process fluids to ensure thedesired heat transfer is accomplished with the heat transfer module'scompressor operating near optimum efficiency.

Heat transfer modules used in connection with the present invention canbe self-contained, engineered structures that include pumps, heatexchangers, compressors, instrumentation, valves and a control system ina unitized housing. Heat transfer modules can be deployed for thepurpose of energy conservation in commercial, industrial, and utilityapplications. A common example of a heat transfer module is a heat pumpunit. One or more heat transfer modules (and related process equipment)can be engineered, designed, installed, and/or maintained in acommercial, industrial or utility application.

BRIEF DESCRIPTION OF FIGURES

The following figures are illustrative of particular embodiments of thepresent invention and therefore do not limit the scope of the invention.The figures are intended for use in conjunction with the explanations inthe following detailed description. Embodiments of the present inventionwill hereinafter be described in conjunction with the appendedphotographs, wherein like numerals denote like elements.

FIGS. 1A-1B are schematic diagrams of illustrative systems fortransferring heat energy from a cooling fluid to a warming fluid via aheat transfer module in an industrial application.

FIG. 2 is a schematic diagram of an illustrative system for transferringheat energy from a cooling fluid to a warming fluid via two heattransfer modules in an industrial application.

FIG. 3 is a schematic diagram of an illustrative system for transferringheat energy from a cooling fluid to two warming fluids via two heattransfer modules in an industrial application.

FIG. 4 is a schematic diagram of an illustrative system for using a heattransfer module to reduce the volume of water handled by a coolingtower.

FIG. 5 is a schematic diagram of an illustrative system for using heattransfer modules to draw heat from cooling water and to warm ambient airin preparation for drying distilled grain in an ethanol productionfacility.

FIG. 6 is a schematic diagram of an illustrative system for using heattransfer modules to draw heat from cooling water and to regulate flowproperties of water passing from a scrubber to a subsequent process inan ethanol production facility.

FIG. 7 is a schematic diagram of an illustrative system for using heattransfer modules to draw heat from cooling water and well water and towarm water before it enters a cook system in an ethanol productionfacility.

FIG. 8 is a schematic diagram of an illustrative system for using heattransfer modules to draw heat from cooling water and to warm well waterbefore it is used for various purposes in an ethanol productionfacility, thereby off-loading downstream heating requirements that wouldotherwise be achieved with traditional heating systems (e.g., steamboilers).

FIG. 9A is a perspective view of an illustrative liquid-to-vapor/gasheat transfer module according to some embodiments of the presentinvention.

FIG. 9B is a perspective view of an illustrative liquid-to-liquid heattransfer module according to some embodiments of the present invention.

FIG. 10 is a schematic diagram of an illustrative system for controllingvarious components of a heat transfer module.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The following detailed description is exemplary in nature and is notintended to limit the scope, applicability, or configuration of theinvention in any way. Rather, the following description providespractical illustrations for implementing exemplary embodiments of thepresent invention. Examples of constructions, materials, dimensions, andmanufacturing processes are provided for selected elements, and allother elements employ that which is known to those of skill in the fieldof the invention. Those skilled in the art will recognize that many ofthe examples provided have suitable alternatives that can be utilized.

FIGS. 1A-1B show systems for using a heat transfer module 2 in anindustrial process to remove heat from a cooling fluid and provide heatto a warming fluid. The heat transfer module 2 can include a compressor6, a condenser heat exchanger 8, an expansion valve 10, and anevaporator heat exchanger 4. Refrigerant circulates through the heattransfer module 2, getting warmer as it passes through the compressor 6toward the condenser heat exchanger 8, shedding heat in the condenserheat exchanger 8, getting cooler as it passes through the expansionvalve 10 toward the evaporator heat exchanger 4, taking on heat in theevaporator heat exchanger 4, and cycling back through the compressor 6.

The refrigerant typically sheds heat to one fluid (e.g., liquid, vapor,gas, etc.) in the condenser heat exchanger 8 and takes on heat from adifferent fluid in the evaporator heat exchanger 4. As shown in FIGS.1A-1B, the refrigerant circulating through the heat transfer module 2can take on heat from a fluid flowing toward a cooling industrialsub-process in the evaporator heat exchanger 4. One example of coolingindustrial sub-process is condensing unwanted components out ofvapor/gas streams (e.g., scrubbing pollutants out of an industrial wastestream). Another common example of a cooling industrial sub-process isremoving heat from industrial equipment (e.g., a fermentation vessel inan ethanol production process). Other examples of cooling industrialsub-processes come from the food processing industry, such as coolingcans in a large-scale vegetable canning plant to ambient temperatureafter the food inside has been cooked and/or pasteurized or freezingprepared food after it has been cooked and packaged. Embodiments of thepresent invention work with and enhance many kinds of cooling industrialsub-processes. In some systems, the cooling fluid enters the evaporatorheat exchanger 4 from a previous industrial sub-process. In somesystems, the cooling fluid enters the evaporator heat exchanger 4 from afluid source (e.g., a well).

FIGS. 1A-1B also shows that the refrigerant circulating through the heattransfer module 2 can shed heat to a fluid flowing toward a warmingindustrial sub-process in the condenser heat exchanger 8, like aconventional heat pump. In this way, heat from the cooling fluid can betransferred to the warming fluid through the refrigerant via theevaporator heat exchanger 4 and the condenser heat exchanger 8. Oneexample of a warming industrial sub-processes is drying elements beingprocessed (e.g., distilled grain in an ethanol production process).Another example is heating various processing equipment (e.g., equipmentfor warming cold corn flour during winter months leading to the slurrysystem where hot water is added). Another common example is pre-heatingfluids before they enter processing vessels, such as warming waterbefore it enters an ethanol cook system, pre-warming cold influent wellwater prior to process systems requiring heat for process effect,warming well water to propagate yeast, and so on. In some systems, thewarming fluid enters the condenser heat exchanger 8 from a previousindustrial sub-process. In some systems, the warming fluid enters thecondenser heat exchanger 8 from a fluid source (e.g., ambient air). Thewarming fluid can enter the condenser heat exchanger 8 from a fluidsource and the cooling fluid can enter the evaporator heat exchanger 4from a previous industrial sub-process, or the warming fluid can enterthe condenser heat exchanger 8 from a previous industrial sub-processand the cooling fluid can enter the evaporator heat exchanger 4 from afluid source—many combinations are possible.

Heat transfer modules according to embodiments of the present inventionthat are used in industrial applications can have important differencesfrom heat pumps used in HVAC applications. One key difference relates tohow the two heat transfer modules are controlled. In HVAC applications,precise input and output parameters (e.g., temperature, flow rate, etc.)are generally less important than in industrial applications. Heattransfer modules for HVAC applications specifically endeavor to providea heating or cooling effect for ambient conditioning. Minor variationsin HVAC fluid parameters tend to have little effect on the overallcomfort of the conditioned space. Moreover, because noticeable changesin the overall comfort of the conditioned space tend to occur slowly,heat transfer module operation adjustments can usually be made quicklyenough to prevent any discomfort in the conditioned space. In contrast,if the heat transfer module does not precisely control warming/coolingfluid parameters in industrial applications, significant downstreamconsequences can result. Additionally, in HVAC applications, if the heattransfer module is cooling the conditioned space, what happens to theheat drawn out of the space is typically of little concern. Likewise, ifthe heat transfer module is heating the conditioned space, the effect onthe environment from which the heat is drawn is typically of littleconcern. In contrast, when heat transfer module embodiments according tothe present invention are used in industrial applications, they mustusually be controlled to account for both the cooling fluid parametersand the warming fluid parameters because the fluids will be used inseparate industrial sub-processes. For these and other reasons, precisecontrol of fluid parameters is of greater importance for industrial heattransfer modules according to embodiments of the present invention thanfor HVAC heat transfer modules. Another key difference between heattransfer modules used in HVAC applications and heat transfer modulesaccording to embodiments of the present invention that are used inindustrial applications is that the metallurgy of one or more of theheat exchangers 4, 8 must often be modified to accommodate cooling orwarming fluids in industrial applications because chemicals in thecooling or warming fluids may erode heat exchangers in standard heattransfer modules.

Although heat pump units are perhaps the most common heat transfermodule used in connection with the present invention, other heattransfer modules can be used. For example, a reverse-acting screwcompressor can replace an expansion valve in some embodiments. Such acompressor can be configured to achieve the same degree of expansion aswould be achieved by the expansion valve. An advantage of thisconfiguration, however, is that the reverse-acting screw compressor isable to convert the refrigerant expansion into mechanical energy. Suchmechanical energy can be used to turn a generator, drive a pump,compress air, and so on. Other heat transfer modules, with differentconfigurations of pumps, heat exchangers, compressors, instrumentation,valves, and/or controllers, can be used, depending on the type ofindustrial process and a variety of other factors.

As can be seen, the systems of FIGS. 1A-1B lack an energy field orcentralized energy storage. The illustrated systems do not need to storeheat energy. Such systems use modulating/digital heat transfer modules(or multiple heat transfer modules used in parallel—see, e.g., FIGS.5-8), along with the application of industrial control methods thatprocess multiple inputs and derive multiple outputs with high levels ofspeed and accuracy (discussed in greater detail in connection with FIG.10). In this way, the systems can monitor the energy needs of both theheating and cooling processes simultaneously and modulate the BTU outputof the system to match the output to the smaller energy need. Forexample, suppose the cooling industrial sub-process involved shedding XBTUs to the cooling fluid and the yet-to-be-cooled cooling fluid wassuited to take on only 0.75X BTUs. Assuming a constant cooling fluidflow rate, that would mean that the cooling fluid would have to shed0.25X BTUs either to the heat transfer module refrigerant or to othercooling means (e.g., a cooling tower) before entering the coolingindustrial sub-process. Suppose also that the warming industrialsub-process involved taking on 2X BTUs from the warming fluid and theyet-to-be-warmed warming fluid was suited to provide only 1.25X BTUs.Again, assuming a constant warming fluid flow rate, that would mean thatthe warming fluid would have to take on 0.75X BTUs either from the heattransfer module refrigerant or from other warming means (e.g., a steamboiler). In this scenario, the cooling fluid would shed 0.25X BTUs tothe heat transfer module refrigerant, which would then be provided tothe warming fluid. That would mean that the warming fluid would have totake on 0.25X BTUs from other warming means. This results in no excessenergy being generated that would require storage in a centralizedenergy field. With this system 100% of the heat energy that is drawninto the refrigerant in the evaporator heat exchanger 4 is shed from therefrigerant in the condenser heat exchanger 8 to the warming fluid.

As noted above, eliminating the need for an energy field or centralizedenergy storage can provide several advantages. In a typical heattransfer module application (such as a geothermal heating/coolingsystem) the construction of the energy field can exceed 50% of the totalproject cost. In addition energy fields require a significant amount ofphysical space that in many potential applications is simply notavailable. Furthermore, transferring energy into and out of thecentralized storage system itself requires energy reducing the overallsystem efficiency. Transferring heat energy from the cooling fluid tothe warming fluid by way of the heat transfer module can result in verysignificant efficiency improvements.

FIGS. 2-3 show systems for using two heat transfer modules 2, 12 in anindustrial process to remove heat from a cooling fluid and provide heatto a warming fluid. Like the first heat transfer module 2, the secondheat transfer module 12 can include a compressor 16, a condenser heatexchanger 18, an expansion valve 20, and an evaporator heat exchanger14. The second heat transfer module 12 can function like the first heattransfer module 2. In many embodiments, cooling fluid can pass from aprevious industrial sub-process or a fluid source through the first andsecond heat transfer modules 2, 12 in parallel, with both heat transfermodules 2, 12 operating at the same or similar parameters. In someembodiments, the cooling fluid can pass from a previous industrialsub-process or a fluid source through the first and second heat transfermodules 2, 12 in series, with the first heat transfer module 2extracting one quantity of heat from the cooling fluid and the secondheat transfer module 12 extracting another quantity of heat from thecooling fluid. In many embodiments, warming fluid can pass from aprevious industrial sub-process or a fluid source through the first andsecond heat transfer modules 2, 12 in parallel, with both heat transfermodules 2, 12 operating at the same or similar parameters. In someembodiments, the warming fluid can pass from a previous industrialsub-process or a fluid source through the first and second heat transfermodules 2, 12 in series, with the first heat transfer module 2 providingone quantity of heat to the warming fluid and the second heat transfermodule 12 providing another quantity of heat to the warming fluid.

The first and second heat transfer modules 2, 12 can receive warmingand/or cooling fluids from the same or different sources and can providewarming and/or cooling fluids to the same or different industrialsub-processes. In FIGS. 2-3, the first and second heat transfer modules2, 12 receive cooling fluid from a previous industrial sub-process andprovide cooling fluid to a first cooling industrial sub-process. In somesystems, the first and second heat transfer modules 2, 12 can receivecooling fluid from two different sources and provide cooling fluid tothe first cooling industrial sub-process. In some systems, the first andsecond heat transfer modules 2, 12 can receive cooling fluid from twodifferent sources and provide cooling fluid to two different coolingindustrial sub-processes. In some systems, the first and second heattransfer modules 2, 12 can receive cooling fluid from a common sourceand provide cooling fluid to two different cooling industrialsub-processes. In FIG. 2, the first and second heat transfer modules 2,12 receive warming fluid from a previous industrial sub-process andprovide warming fluid to a first warming industrial sub-process. In somesystems, the first and second heat transfer modules 2, 12 can receivewarming fluid from two different sources and provide warming fluid tothe first warming industrial sub-process. In FIG. 3, the first andsecond heat transfer modules 2, 12 receive warming fluid from twodifferent sources (the first heat transfer module 2 from a fluid sourceand the second heat transfer module 12 from a previous industrialsub-process) and provide warming fluid to two different warmingindustrial sub-processes (the first heat transfer module 2 to a firstwarming industrial sub-process and the second heat transfer module 12 toa second warming industrial sub-process). In some systems, the first andsecond heat transfer modules 2, 12 can receive warming fluid from acommon source and provide warming fluid to two different warmingindustrial sub-processes. Many combinations of input and outputcooling/warming fluids are possible.

Many systems employ more than two heat transfer modules. In somesystems, three, four, five, or more heat transfer modules can beemployed. In such systems, some or all of the heat transfer modules canreceive cooling fluid from the same source. In such systems, some or allof the heat transfer modules can receive warming fluid from the samesource. In such systems, some or all of the heat transfer modules canprovide cooling fluid to the same cooling industrial sub-process. Insuch systems, some or all of the heat transfer modules can providewarming fluid to the same warming industrial sub-process. In suchsystems, the various heat transfer modules can receive warming and/orcooling fluids from multiple sources. In such systems, the various heattransfer modules can provide warming and/or cooling fluids to multipleindustrial sub-processes. Again, many combinations of input and outputcooling/warming fluids are possible for systems employing multiple heattransfer modules.

FIG. 4 shows a system for minimizing an amount of water that is cooledvia a cooling tower in an industrial process. One drawback to coolingwater (or other fluids) via a cooling tower is that significantquantities of water are lost due to evaporation. The volume of waterthat exits the cooling tower can be less than the volume of water thatenters the cooling tower because of evaporative loss. Over time, theselosses add up to volumes of water that are quite substantial.Additionally, water must be added to the system to compensate for theselosses, meaning that the cooling system is not a closed-loop system.Another issue involves the chemicals that are often added to the waterto treat for corrosion, iron, contaminants, etc. When the waterevaporates, these chemicals are also lost. Thus, it is desirable tobypass the cooling tower with as much water as possible, cooling itinstead with alternative equipment.

In the system of FIG. 4, some of the water that would otherwise becooled with the cooling tower is diverted into the first heat transfermodule 2 from a return line flowing toward the cooling tower from anindustrial heat exchanger. The water in the return line is warmer thanthe water in the supply line because the water takes on heat from theindustrial equipment being cooled by the industrial heat exchanger. Thequantity of water that is diverted from the return line can becirculated through the evaporator heat exchanger 4, where the water canshed heat to the heat transfer module refrigerant. The water can then beintroduced back into the supply line flowing from the cooling towertoward the industrial heat exchanger. In many systems, the water exitingthe evaporator heat exchanger 4 is at a lower temperature than the waterin the supply line. This can also reduce the total water quantityrequired to cool the relevant industrial equipment, as colder supplyline water means that less supply line volume is required to accomplishthe same cooling. In many embodiments, return line water is divertedthrough multiple heat transfer modules (in parallel and/or in series) toaccomplish cooling other than through the cooling tower. In someembodiments, the cooling tower can be entirely replaced by several heattransfer modules operating as described herein.

Bypassing the cooling tower, as shown in FIG. 4, can be incorporatedinto many systems with a variety of different characteristics. As shownin FIG. 4, warming fluid can be circulated through the condenser heatexchanger 8 of the heat transfer module 2 according to any of themanners discussed herein. In this way, heat that the cooling fluid tookon at the industrial heat exchanger can be transferred to the warmingfluid through the heat transfer module refrigerant via the evaporatorheat exchanger 4 and the condenser heat exchanger 8.

Heat transfer modules discussed herein can be configured to work with avariety of cooling fluids and a variety of heating fluids. Somepreferred heat transfer modules are configured to accommodate coolingfluid and warming fluid that are both liquid. Such heat transfer modulesare often called liquid-to-liquid heat transfer modules. Examplesinclude water-to-water, and so on. One example of a liquid-to-liquidheat transfer module is shown in FIG. 9B. Some preferred heat transfermodules are configured to accommodate cooling fluid that is liquid andwarming fluid that is vapor/gas. Such heat transfer modules are oftencalled liquid-to-gas heat transfer modules. Examples includewater-to-air, water-to-vapor, and so on. One example of aliquid-to-liquid heat transfer module is shown in FIG. 9A. Some heattransfer modules are configured to accommodate cooling fluid that isvapor/gas and warming fluid that is liquid. Some heat transfer modulesare configured to accommodate cooling fluid that is vapor/gas andwarming fluid that is vapor/gas. Other combinations of cooling fluidsand warming fluids can be accommodated by heat transfer modulesaccording to embodiments of the present invention.

FIGS. 5-8 show illustrative systems according to embodiments of thepresent invention for use in ethanol production facilities. Theillustrative heat transfer modules shown in FIGS. 5-8 includeliquid-to-air modulating heat transfer modules 102, liquid-to-liquidmodulating heat transfer modules 104, and liquid-to-liquid two stageheat transfer modules 104′. Ethanol production facilities, or ethanolplants, involve several cooling sub-processes and several warmingsub-processes in which fluids carry away or deliver heat. Often, fluidsused in an ethanol production facility carry away heat and simplydispense it into the atmosphere. The heat is not recycled for otheruses. Similarly, heating fluids in ethanol production facilities (e.g.,via steam boilers, hot water boilers, direct-fired burners, exothermicprocesses such as fermentation, etc.) typically consumes large amountsof energy. Thus, because many embodiments of the present inventioninvolve recycling waste heat energy for use in warming sub-processes,such embodiments of the present invention can provide very significantenergy savings for ethanol production facilities.

Additionally, and perhaps more importantly, embodiments of the presentinvention can substantially reduce the volume of water consumed in aconventional ethanol production facility. As is discussed in greaterdetail below, a fermentation vessel in an ethanol production facilityproduces large quantities of heat and is the subject of significantcooling efforts. If the fermentation vessel is not cooled properly, theperformance of the fermentation enzymes is inhibited. In conventionalethanol plants, very large volumes of cooling water are circulatedthrough a loop that includes a cooling tower and a fermentation vesselheat exchanger. The water draws in heat energy in the fermentationvessel heat exchanger and sheds that heat in the cooling tower. But asis mentioned above, considerable quantities of water are lost in coolingtowers due to evaporation. In some systems, the volume of water flowinginto the cooling tower is up to 1.3% greater than the volume of waterflowing out of the cooling tower. While this may not sound like a largeloss, when one considers that the average dry mill ethanol plant canhave a flow rate of 55,000 gpm, small losses can add up quickly.

Additionally, reducing the evaporative loss at the cooling tower canhave a cascading effect on water use throughout the ethanol productionfacility. The water that is lost through evaporation has to be “made-up”by supplying more water into the system. These additional quantities ofwater must be treated, filtered, softened, and otherwise conditioned tomake them suitable for use in the process. Treatment methods for waterentering a process plant can include:

-   -   Chemical treatment systems which require the purchase of various        chemical agents to neutralize undesired water properties    -   Filtration systems such as water softening, media filters, and        reverse osmosis systems. These system require regeneration        cycles and may still require chemical use (e.g., water softeners        may utilize a sodium based brine as a regeneration agent). The        regeneration water is typically discharged from the plant.        These illustrative treatment processes not only increase water        use for the regeneration cycle, they also require that the        regenerated water be discharged from the plant. The cascading        effect of reducing evaporative loss dramatically reduces the        plant discharge as well. The design parameters of a system        capable of delivering 3.19 million BTUs of cooling at an ethanol        facility would result in up to 309 million gallons of water        bypassing the cooling tower each year. The cascading effect of        eliminating the evaporative loss of this water will reduce well        water use by over 10 million gallons annually and will reduce        the facilities discharge by over 6.5 million gallons annually.

Thus, because many embodiments of the present invention involve coolingquantities of water with heat transfer modules, thereby bypassing thecooling tower and its associated evaporative loss, such embodiments ofthe present invention can provide very significant water savings forethanol production facilities.

In the systems shown in FIGS. 5-8, the heat transfer modules can, ifdesired, be removed or isolated from the other components of the system.Valves can be adjusted to temporarily or permanently channel fluid towhere it would be channeled in the absence of any heat transfer modules.None of the existing equipment need be modified in order to install theheat transfer modules. This can be useful if one or more of the heattransfer modules is in need of repair or if a decision is made toeliminate the heat transfer modules from the industrial processaltogether. For example, valves can be adjusted to stop diverting waterfrom the cooling tower return line to the heat transfer modules,allowing instead all of the water to pass through the cooling tower. Inanother example, valves can be adjusted to stop channeling water thatexits the carbon dioxide scrubber to the heat transfer modules, allowinginstead all of the water to pass directly to the cook system. Thisfeature, which can be referred to as the heat transfer modules'“bolt-on” capability, can be useful in many ethanol-related applicationsas well other industrial applications. In this way, going back to thesystem as it existed prior to the addition of the heat transfer modulescan be accomplished with relative ease.

In many of the systems discussed herein, cooling fluid bound for acooling industrial sub-process is routed directly through the evaporatorheat exchanger of a heat transfer module, or warming fluid bound for awarming industrial sub-process is routed directly through the condenserheat exchanger of a heat transfer module. In many systems, however, thecooling/warming fluid need not be routed directly through the relevantheat exchanger of the heat transfer module. Instead, the cooling/warmingfluid can be routed through a separate heat exchanger in which thecooling/warming fluid sheds/draws heat energy from a fluid that is inthermal communication with the relevant heat exchanger of the heattransfer module.

FIG. 10 shows an illustrative system for transferring energy from oneprocess fluid to another in an industrial process. The system caninclude a heat transfer module 202, such as those discussed elsewhereherein, with a compressor 206, a condenser heat exchanger 208, anexpansion valve 210, and an evaporator heat exchanger 204. A coolingfluid can enter the evaporator heat exchanger 204, where it can shedheat energy to refrigerant flowing through the heat transfer module 202.The refrigerant can transfer that heat energy to a warming fluid in thecondenser heat exchanger 208, thereby eliminating any need for centralenergy storage. It should be understood that systems incorporatingconcepts illustrated in FIG. 10 can be used in many settings other thanindustrial processes, such as the following:

-   -   District Heating and Cooling Plants    -   Commercial Laundry Facilities    -   Central Plant Heating and Cooling Systems        -   >Hotels/Resorts        -   >Hospitals        -   >Institutional Facilities (Schools, Universities, Prisons)    -   Dehumidification Systems        -   >Ice Arena        -   >Indoor Swimming Pool Areas        -   >Indoor Water Parks    -   Merchant Power Utility

The system can include a heat transfer module refrigerant sensingmechanism that senses various attributes of the refrigerant duringoperation of the heat transfer module 202. The refrigerant sensingmechanism of FIG. 10 includes a suction pressure sensor 212, which canbe configured to regularly measure a suction pressure value for thecompressor 206 during operation of the heat transfer module 202. Therefrigerant sensing mechanism of FIG. 10 further includes a dischargepressure sensor 214, which can be configured to regularly measure adischarge pressure value for the compressor 206 during operation of theheat transfer module 202. The refrigerant sensing mechanism of FIG. 10further includes a suction temperature sensor 216 and a dischargetemperature sensor 218, which can be configured to regularly measure asuction temperature value and a discharge temperature value,respectively, during operation of the heat transfer module 202. Variousother sensors, aimed at sensing various attributes of the refrigerant,can be incorporated into embodiments of the refrigerant sensingmechanism.

In preferred embodiments, the system can include a compressor controller220 configured to ensure that the compressor 206 operates at as close tooptimum efficiency as possible. When compressors operate near optimumefficiency, less energy input is required, and the compressors lastlonger and require less maintenance. In some embodiments, a keycomponent in ensuring that the compressor 206 operates near optimumefficiency is the pressure differential of the refrigerant across thecompressor 206 (i.e., the discharge pressure minus the suctionpressure). If that pressure differential is too low or too high, thecompressor 206 does not operate as efficiently and is at increased riskof breaking down. Based upon the application in which the compressor isapplied, the compressor will have a “sweet spot” pressure differentialrange within which it operates most efficiently, and the compressorcontroller 220 aims to keep the compressor 206 within that range. Thecompressor controller 220 can be configured to receive the suctionpressure value and the discharge pressure value from the refrigerantsensing mechanism. With that information, the compressor controller 220can be configured to compare the suction pressure value to the dischargepressure value to determine an operational pressure differential.

As noted, the compressor controller 220 can be configured to maintainthe operational pressure differential within a predetermined range. Ifthe operational pressure differential is too high, the compressorcontroller 220 can take steps to reduce it. If the operational pressuredifferential is too low, the compressor controller 220 can take steps toincrease it. The compressor controller 220 can take such steps bycausing one or more of several variables to be adjusted. In someembodiments, the compressor controller 220 can cause the temperatureand/or pressure and/or flow rate of a cooling fluid entering theevaporator heat exchanger 204 to be adjusted. In some embodiments, thecompressor controller 220 can cause the temperature and/or pressureand/or flow rate of a warming fluid entering the condenser heatexchanger 208 to be adjusted. Some illustrative ways of causing suchadjustments are discussed below.

The system of FIG. 10 includes a cooling fluid controller 222 and awarming fluid controller 224. Some systems can include only one or theother. The compressor controller 220 can be configured to cause thepressure and/or the flow rate of the cooling fluid to be adjusted bycommunicating instructions to the cooling fluid controller 222. Thecooling fluid controller 222 can be configured to cause adjustment to acooling fluid inlet pump 226. The compressor controller 220 can beconfigured to cause the pressure and/or the flow rate of the warmingfluid to be adjusted by communicating instructions to the warming fluidcontroller 224. The warming fluid controller 224 can be configured tocause adjustment to a warming fluid inlet pump 228. As is discussed ingreater detail below, there are several advantages to being able toadjust different parameters of different process fluids in differentapplications.

In systems that involve a compressor controller 220, a warming fluidcontroller 224, and a cooling fluid controller 222, the threecontrollers can be programmed to limit the speed at which the outputvalue adjusts. If the output values are all adjusted at the same rate ofspeed, each controller may seek to make adjustments on an almostcontinuous basis, never allowing the system to reach any kind of steadystate. Cascading the controllers, or setting them to adjust theiroutputs at different rates of speed allows the lagging (slower-acting)controllers to react to adjustments made by the leading (faster-acting)controllers. For example, in preferred embodiments, one of the warmingfluid controller 224 or the cooling fluid controller 222 can beconfigured to cause adjustment to the warming fluid inlet pump 228 orthe cooling fluid inlet pump 226, respectively, at a first rate of speed(e.g., the output can adjust 1% in one second). The other of the warmingfluid controller 224 or the cooling fluid controller 222 can beconfigured to cause adjustment to the warming fluid inlet pump 228 orthe cooling fluid inlet pump 226, respectively, at a second rate ofspeed (e.g., the output can adjust 1% in two seconds), which is slowerthan the first rate of speed. The compressor controller 220 can beconfigured to communicate instructions to the warming fluid controller224 and/or the cooling fluid controller 222 at a third rate of speed(e.g., the output can adjust 1% in three seconds), which is slower thanthe second rate of speed. It should be understood that otherconfigurations may be employed for other systems and/or differentcontrollers.

As noted, in some embodiments, the compressor controller 220 can beconfigured to cause the temperature of the cooling fluid and/or thetemperature of the warming fluid to be adjusted. In many suchembodiments, the cooling fluid inlet pump 226 and the warming fluidinlet pump 228 may have little or no ability to adjust the temperatureof the respective fluids. In such embodiments, adjustments to thetemperature can be made upstream of the fluid inlet pumps. Thecompressor controller 220 can be configured to cause the temperature ofthe cooling fluid and/or the temperature of the warming fluid to beadjusted by communicating instructions to one or more facility processcontrollers 230, 232. The facility process controllers 230, 232 can beresponsible for controlling one or more processes at a facility intowhich one or more heat transfer modules are incorporated. In preferredembodiments, the facility process controllers 230, 232 can be configuredto cause adjustment to one or more portions of the industrial process,thereby adjusting the temperature of the respective fluids before thereach the fluid inlet pumps.

Systems discussed herein that permit selective adjustment of thetemperature and/or pressure and/or flow rate of one or more processfluids can provide a variety of advantages. For instance, such a systemcan account for situations in which one or more parameters of an inputprocess fluid are dictated by the process itself and are not adjustable.For example, if the flow rate of the cooling fluid is fixed, thetemperature and/or pressure of the cooling fluid can be adjusted inorder to maintain the desired outputs. If the flow rate of the warmingfluid is fixed, the temperature and/or pressure of the warming fluid canbe adjusted in order to maintain the desired outputs. In addition, ifboth the cooling and warming fluid flow rates are fixed, the facilityprocess controllers can be deployed to adjust to the desired outputs. Insome embodiments, such selective adjustment can be an important factorin eliminating the need for central energy storage. Such selectiveadjustment can allow the ability to maintain process set point targetson both the warming fluid and cooling fluid sides of the system, asopposed to just one side or the other. Many systems such as thosediscussed herein allow optimization of energy consumption, with moreperformance output being provided per unit of energy input. Selectiveadjustment of multiple process fluid parameters can further enable thesystem to operate across the entire range of the performance window ofthe refrigerant, as opposed to using only part of the refrigerantperformance range.

In a first aspect, the present invention involves a method of heatingand cooling fluids for use in an industrial process. The method caninclude providing a heat transfer module that includes a condenser heatexchanger and a evaporator heat exchanger. The method can includecirculating a refrigerant through the heat transfer module. The methodcan include circulating a cooling fluid through the evaporator heatexchanger, thereby removing heat from the cooling fluid and preparingthe cooling fluid for a cooling industrial sub-process. The method caninclude circulating a warming fluid through the condenser heatexchanger, thereby adding heat to the warming fluid and preparing thewarming fluid for a warming industrial sub-process. The method caninclude supplying the cooling fluid from an outlet of the evaporatorheat exchanger to equipment for performing the cooling industrialsub-process. The method can include supplying the warming fluid from anoutlet of the condenser heat exchanger to equipment for performing thewarming industrial sub-process.

As alluded to elsewhere herein, the method of the first aspect can beused in connection with a variety of warming and cooling industrialsub-processes. For example, the cooling industrial sub-process caninclude (a) scrubbing carbon dioxide out of a fermentation vessel'swaste stream in an ethanol production process; (b) cooling afermentation vessel; (c) a food-related process; or (d) other coolingindustrial sub-process. Also, for example, the warming industrialsub-process can include (a) warming water before it enters an ethanolcook system; (b) drying distilled grain in a dryer; or (c) other warmingindustrial sub-process.

In a second aspect, the present invention involves a method oftransferring energy from one sub-process to another in an industrialprocess. The method can include providing a heat transfer module thatincludes a condenser heat exchanger and a evaporator heat exchanger. Themethod can include circulating a refrigerant through the heat transfermodule. The method can include transferring energy (i) from a coolingfluid flowing toward a cooling industrial sub-process (ii) through therefrigerant via the evaporator heat exchanger and the condenser heatexchanger (iii) to a warming fluid flowing toward a warming industrialsub-process.

As alluded to elsewhere herein, the method of the second aspect can beused in connection with a variety of warming and cooling industrialsub-processes. For example, the cooling industrial sub-process caninclude (a) scrubbing carbon dioxide out of a fermentation vessel'swaste stream in an ethanol production process; (b) cooling afermentation vessel; (c) a food-related process; or (d) other coolingindustrial sub-process. Also, for example, the warming industrialsub-process can include (a) warming water before it enters an ethanolcook system; (b) drying distilled grain in a dryer; or (c) other warmingindustrial sub-process.

In a third aspect, the present invention involves a method of minimizingan amount of water that is cooled via a cooling tower in an industrialprocess. The method can include providing a heat transfer module thatincludes a condenser heat exchanger and a evaporator heat exchanger. Themethod can include circulating a refrigerant through the heat transfermodule. The method can include diverting a water quantity from a returnline flowing toward the cooling tower from an industrial heat exchanger,the water quantity having been warmed in the industrial heat exchanger.The method can include circulating the water quantity through theevaporator heat exchanger, thereby removing heat from the water quantityand preparing the water quantity to return to the industrial heatexchanger. The method can include introducing the water quantity into asupply line flowing from the cooling tower toward the industrial heatexchanger, thereby bypassing the cooling tower. In some embodiments,circulating the first water quantity through the evaporator heatexchanger further includes transferring heat (i) from the water quantity(ii) through the refrigerant via the evaporator heat exchanger and thecondenser heat exchanger (iii) to a warming fluid flowing toward awarming industrial sub-process. In some embodiments, the industrial heatexchanger comprises a fermentation vessel heat exchanger. Methods inaccordance with this aspect of the invention can incorporate any of thefeatures discussed elsewhere herein.

In the foregoing detailed description, the invention has been describedwith reference to specific embodiments. However, it may be appreciatedthat various modifications and changes can be made without departingfrom the scope of the invention. Thus, some of the features of preferredembodiments described herein are not necessarily included in preferredembodiments of the invention which are intended for alternative uses.

1. A method of heating and cooling fluids for use in an industrial ornon-industrial process without need for an energy field or centralizedenergy storage, the method comprising: (a) providing a first heattransfer module that includes a first condenser heat exchanger and afirst evaporator heat exchanger; (b) circulating a first refrigerantthrough the first heat transfer module; (c) circulating a first coolingfluid through the first evaporator heat exchanger, thereby removing heatfrom the first cooling fluid and preparing the first cooling fluid for afirst cooling sub-process; (d) circulating a first warming fluid throughthe first condenser heat exchanger, thereby adding heat from the firstrefrigerant to the first warming fluid and preparing the first warmingfluid for a first warming sub-process; (e) supplying the first coolingfluid from an outlet of the first evaporator heat exchanger to equipmentfor performing the first cooling sub-process; and (f) supplying thefirst warming fluid from an outlet of the first condenser heat exchangerto equipment for performing the first warming sub-process.
 2. The methodof claim 1, further comprising: (g) providing a second heat transfermodule that includes a second condenser heat exchanger and a secondevaporator heat exchanger; (h) circulating a second refrigerant throughthe second heat transfer module; (i) circulating a second cooling fluidthrough the second evaporator heat exchanger, thereby removing heat fromthe second cooling fluid and preparing the second cooling fluid for thefirst cooling sub-process; and (j) supplying the second cooling fluidfrom an outlet of the second evaporator heat exchanger to the equipmentfor performing the first cooling sub-process.
 3. The method of claim 2,further comprising: (k) circulating a second warming fluid through thesecond condenser heat exchanger, thereby adding heat from the secondrefrigerant to the second warming fluid and preparing the second warmingfluid for the first warming sub-process; and (l) supplying the secondwarming fluid from an outlet of the second condenser heat exchanger tothe equipment for performing the first warming sub-process.
 4. Themethod of claim 2, further comprising: (k) circulating a second warmingfluid through the second condenser heat exchanger, thereby adding heatfrom the second refrigerant to the second warming fluid and preparingthe second warming fluid for a second warming sub-process; and (l)supplying the second warming fluid from an outlet of the secondcondenser heat exchanger to the equipment for performing the secondwarming sub-process.
 5. The method of claim 4, wherein the first warmingfluid is a liquid and the second warming fluid is a gas/vapor.
 6. Themethod of claim 1, further comprising: (g) providing a second heattransfer module that includes a second condenser heat exchanger and asecond evaporator heat exchanger; (h) circulating a second refrigerantthrough the second heat transfer module; (i) circulating a secondcooling fluid through the second evaporator heat exchanger, therebyremoving heat from the second cooling fluid and preparing the secondcooling fluid for a second cooling sub-process; and (j) supplying thesecond cooling fluid from an outlet of the second evaporator heatexchanger to equipment for performing the second cooling sub-process. 7.The method of claim 6, further comprising: (k) circulating a secondwarming fluid through the second condenser heat exchanger, therebyadding heat from the second refrigerant to the second warming fluid andpreparing the second warming fluid for a second warming sub-process; and(l) supplying the second warming fluid from an outlet of the secondcondenser heat exchanger to the equipment for performing the secondwarming sub-process.
 8. The method of claim 6, further comprising: (k)circulating a second warming fluid through the second condenser heatexchanger, thereby adding heat from the second refrigerant to the secondwarming fluid and preparing the second warming fluid for the firstwarming sub-process; and (l) supplying the second warming fluid from anoutlet of the second condenser heat exchanger to the equipment forperforming the first warming sub-process.
 9. The method of claim 6,wherein the first cooling fluid is a liquid and the second cooling fluidis a gas/vapor.
 10. The method of claim 1, wherein the first coolingfluid and the first warming fluid are both liquid.
 11. (canceled) 12.The method of claim 1, wherein the first cooling fluid is a liquid andthe first warming fluid is a gas/vapor.
 13. The method of claim 12,wherein the first cooling fluid is water and the first warming fluid isair. 14-16. (canceled)
 17. A method of transferring energy from oneprocess fluid to another in an industrial or non-industrial processwithout need for an energy field or centralized energy storage, themethod comprising: (a) providing a first heat transfer module thatincludes a first condenser heat exchanger and a first evaporator heatexchanger; (b) circulating a first refrigerant through the first heattransfer module; and (c) transferring energy (i) from a first coolingfluid flowing toward a first cooling sub-process (ii) through the firstrefrigerant via the first evaporator heat exchanger and the firstcondenser heat exchanger (iii) to a first warming fluid flowing toward afirst warming sub-process.
 18. The method of claim 17, furthercomprising: (d) providing a second heat transfer module that includes asecond condenser heat exchanger and a second evaporator heat exchanger;(e) circulating a second refrigerant through the second heat transfermodule; and (f) transferring energy (i) from a second cooling fluidflowing toward the first cooling sub-process (ii) through the secondrefrigerant via the second evaporator heat exchanger and the secondcondenser heat exchanger (iii) to a second warming fluid flowing towardthe first warming sub-process.
 19. The method of claim 17, furthercomprising: (d) providing a second heat transfer module that includes asecond condenser heat exchanger and a second evaporator heat exchanger;(e) circulating a second refrigerant through the second heat transfermodule; and (f) transferring energy (i) from a second cooling fluidflowing toward the first cooling sub-process (ii) through the secondrefrigerant via the second evaporator heat exchanger and the secondcondenser heat exchanger (iii) to a second warming fluid flowing towarda second warming sub-process.
 20. The method of claim 19, wherein thefirst warming fluid is a liquid and the second warming fluid is agas/vapor.
 21. The method of claim 17, further comprising: (d) providinga second heat transfer module that includes a second condenser heatexchanger and a second evaporator heat exchanger; (e) circulating asecond refrigerant through the second heat transfer module; and (f)transferring energy (i) from a second cooling fluid flowing toward asecond cooling sub-process (ii) through the second refrigerant via thesecond evaporator heat exchanger and the second condenser heat exchanger(iii) to a second warming fluid flowing toward a second warmingsub-process.
 22. The method of claim 17, further comprising: (d)providing a second heat transfer module that includes a second condenserheat exchanger and a second evaporator heat exchanger; (e) circulating asecond refrigerant through the second heat transfer module; and (f)transferring energy (i) from a second cooling fluid flowing toward asecond cooling sub-process (ii) through the second refrigerant via thesecond evaporator heat exchanger and the second condenser heat exchanger(iii) to a second warming fluid flowing toward the first warmingsub-process.
 23. (canceled)
 24. The method of claim 17, wherein thefirst cooling fluid and the first warming fluid are both liquid. 25.(canceled)
 26. The method of claim 17, wherein the first cooling fluidis a liquid and the first warming fluid is a gas/vapor. 27-37.(canceled)